At a simple level, sensors are devices that may capture data, and in response provide a signal. The use of sensors is commonly utilized when a need arises to measure and convert physical quantities into signals. Examples of types of sensors include acoustic, chemical, electrical, optical, or flow sensors to name a few.
A wearable computing device may include sensors for sensing any of a number of physical, environmental, or operational elements. A processor of the wearable computing device may be configured to perform actions in response to the signals provided by the sensors. For example, a tactile sensor on a wearable computing device may be used to detect inputs from a user of the wearable computing device. An accelerometer may detect motion of the wearable computing device and provide information to the user.
In one example, eyeglasses with an on-board computing system and projector may be configured as an example of a wearable computing device. The lens elements of the eyeglasses may suitably display a projected image or graphic. The lens elements may also be sufficiently transparent to allow a user to see through the lens element. The two features of the lens elements may be combined to form a heads-up display system. Additionally, the system may be connected to or affixed within a head-mounted structure to create a head-mounted display.